<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        /* 未被点击时 */
        a:link{
            color: red;
        }
        /* 鼠标按下不要松开 */
        a:active{
            color:blue;
        }
        /* 访问后 */
        a:visited{
            color: chartreuse;
        }
        /* 鼠标移动 */
        a:hover{
            color: yellow;   
        }
    </style>
</head>
<body>
    <div>
        <a href="#">欢迎来到蓝桥云课</a>
    </div>
</body>
</html>